The present invention relates to fax machines, and relates more particularly to the transmission unit of a fax machine which prevents the gears from being jammed, and permits jammed paper to be conveniently pulled out of the machine.
The transmission unit of a fax machine comprises a first roller and a second roller. The first roller and the second roller are simultaneously rotated to advance the thermal paper during the copy or incoming mode. When at the outgoing mode, only the first roller is rotated to feed document. After the copy or incoming mode, the thermal paper is cut automatically or manually. When the thermal paper is cut off, the leading end of the rest thermal paper extends over the thermal printing head which cannot be used for printing. Furthermore, because the gears for power transmission from the motor to the first roller are maintained connected when a paper is jammed in the transmission unit, it is difficult to pull the jammed paper out of the transmission unit of the fax machine.